This error occurs when the Redis server fails to start or stop within the systemd-configured timeout period. It typically happens with large databases or when system resources are constrained, causing systemd to terminate the startup process prematurely.
This error indicates that systemd attempted to start the Redis server service but exceeded the configured timeout limit before Redis could complete its initialization. When Redis starts, it needs to load data from disk into memory, validate configurations, and establish its server socket. With large databases or on resource-constrained systems, this process can take longer than the default systemd timeout allows. Systemd uses timeout values (TimeoutStartSec and TimeoutStopSec) to prevent services from hanging indefinitely during startup or shutdown. If Redis doesn't report successful startup within this window, systemd assumes the service has failed and terminates the process, generating this error message. The issue is particularly common after system updates, when migrating to larger datasets, or when Redis is configured with supervised systemd mode but the service file hasn't been updated with appropriate timeout values.
First, verify the current state and examine what happened during the failed startup:
# Check service status
systemctl status redis-server
# View recent logs
journalctl -u redis-server -n 50 --no-pager
# Check Redis log file
sudo tail -n 100 /var/log/redis/redis-server.logLook for messages about loading RDB/AOF files or memory allocation. This will help identify if the timeout is database-size related.
Edit the Redis systemd service file to extend the timeout:
# Create override directory if it doesn't exist
sudo mkdir -p /etc/systemd/system/redis-server.service.d
# Create override file
sudo nano /etc/systemd/system/redis-server.service.d/override.confAdd the following configuration:
[Service]
TimeoutStartSec=300
TimeoutStopSec=300
Type=notifyFor very large databases, you can use:
[Service]
TimeoutStartSec=infinity
TimeoutStopSec=infinity
Type=notifyThen reload systemd and restart Redis:
sudo systemctl daemon-reload
sudo systemctl start redis-server
sudo systemctl status redis-serverEnsure Redis is properly configured for systemd supervision:
# Check Redis configuration
sudo grep -i supervised /etc/redis/redis.confThe output should show:
supervised systemdIf it shows "supervised no" or is commented out, edit the file:
sudo nano /etc/redis/redis.confFind and update the line to:
supervised systemdSave and attempt to start Redis again.
Verify that your system has sufficient resources for Redis startup:
# Check available memory
free -h
# Check disk I/O
iostat -x 2 5
# Monitor system load
topRedis requires enough RAM to load your entire dataset. Check your RDB/AOF file sizes:
# Check database file sizes
ls -lh /var/lib/redis/dump.rdb
ls -lh /var/lib/redis/appendonly.aofIf memory is insufficient, consider:
- Adding more RAM
- Reducing Redis maxmemory setting
- Using Redis eviction policies
- Enabling compression in your Redis configuration
If timeouts persist, optimize Redis for faster startup:
sudo nano /etc/redis/redis.confConsider these optimizations:
# Disable AOF if not needed (faster startup)
appendonly no
# Or reduce AOF fsync frequency
appendfsync everysec
# Disable or reduce background saves during startup
save ""
# Increase I/O threads for faster loading (Redis 6.0+)
io-threads 4
io-threads-do-reads yesAfter changes:
sudo systemctl daemon-reload
sudo systemctl restart redis-serverUnderstanding systemd Type=notify: When using "supervised systemd" in Redis configuration, you must set "Type=notify" in the service file. This tells systemd to wait for Redis to send a notification message when it's ready, rather than assuming it's ready immediately. Without this, systemd may prematurely consider Redis started or failed.
Database loading time estimation: As a rule of thumb, Redis can load approximately 1GB of RDB data in 1-2 seconds on modern hardware with SSD storage. For very large datasets (100GB+), startup times of several minutes are normal. Use "TimeoutStartSec=0" or "TimeoutStartSec=infinity" for production systems with large databases.
Persistence format considerations: AOF files typically load slower than RDB files due to their sequential nature. If you have both enabled, Redis will prefer loading from AOF on startup. Consider using mixed persistence (aof-use-rdb-preamble yes) for faster loading with AOF's durability benefits.
Container environments: If running Redis in Docker or Kubernetes, this error may appear in the host logs if systemd is managing the container runtime. Check both container logs and systemd logs to identify the actual source of the timeout.
Alternative supervision modes: If you continue experiencing issues with systemd supervision, you can use "supervised auto" or "supervised no" in redis.conf, though this provides less integration with systemd's service management features.
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